By Jens Meiners
In response to ever more stringent CO2 emissions regulation, European carmakers are beginning to roll out vehicles fueled by compressed natural gas (CNG). The latest and possibly most advanced of these is the Audi A3 g-tron, which sounds like it might be either a knockoff Transformer or maybe Young Jeezy’s robotic hype man. But it’s just a car. Based on the five-door A3 Sportback, it packs a 110-hp 1.4-liter TFSI engine that produces 148 lb-ft of torque and can combust both regular gasoline and CNG. The g-tron switches to gasoline operation automatically when the onboard CNG runs low, but the switch also can be triggered manually. READ MORE ››